Process for making copolyesters containing ether groups

ABSTRACT

This invention relates to the manufacture of copolyesters containing ether groups, and it has for its object to provide a simple and efficient process for this purpose.

United States Patent I l UN Inventors Herbert Eek;

Hellmuth Spes, both of Burghnusen-Upper Bavaria, Germany Appl. No. 676,048 Filed Oct. 18, I967 Patented Sept. 2 I 1971 Assignce Wacker-Chemie G.m.b.ll.

Munich, Germany Priority Oct. 26, 1966 Germany W 42670 PROCESS FOR MAKING COPOLYESTERS CONTAINING ETHER GROUPS 5 Claims, No Drawings US. Cl 260/473 G, 6 R..2Ql48l 2 0/48 A [5] Int. Cl ..C07c 69/76, C08g 5 H42 [50] Field of Search 260/473, 484

[56] References Cited OTHER REFERENCES Sonn et al., Chem. Abstr., 49: I75 I955) Hurd et al. .lACS 83: 236 (1961) Primary Examiner-Lewis Gotts Assistant Examiner-R. S. Weissberg Attorney-Donald Malcolm ABSTRACT: This invention relates to the manufacture of copolyesters containing ether groups, and it has for its ob ect to provide a simple and efficient process for this purposev BACKGROUND OF THE INVENTION It is known that ketenes react with acetals to form B-alkoxycarboxylic acid esters and with semicyclic acetals, e.g. with methoxytetrahydropyran to form 2-tetrahydropyran, acetate and 3-methoxy-7-hydroxypheptenoate (C.D. Hurd and RD.

Kimbrough, J. Am. Chem. Soc., 1961; page 237; No. 8}).

SUMMARY OF THE INVENTION We have discovered a process for making ether group containing copolyesters of the general formula The process is characterized by the fact that we react polyacetals having the structural unit alone or in admixture with cyclic acetals of the general formuwith ketenes of the general structure (R") C =C =0 the presence of an acid catalyst at temperatures between 80 and l60 C, if necessary using a solvent. In the above formulas:

or a substituted or unsubstituted, monocyclic or polycyclic, aromatic, bivalent residue like for instance perhaps substituted aliphatic residue, substituted or unsubstituted alicyclic, aromatic or heterocyclic residue, where R and R must not react alkaline.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The process can be carried out continuously or discontinuously. Suitable for acid catalysts are mineral acids, e.g. sulfuric acid, phosphoric acid, difluorophosphoric acid, hexafluorophosphoric acid and/or Friedel-Krafts catalysts, e.g. boron trifluoride etherate, aluminum chloride, zinc chloride, iron (III) chloride.

For the catalyst concentration, a quantity of 0.05 percent, referred to the acetal used, is adequate. The upper limit is guided by considerations of economy and generally does not exceed 7 percent. Preferably a catalyst concentration of 0.5 to 5 percent is used.

As solvents all inert solvents are suitable, like ether,

chlorinated hydrocarbons, e.g. methylene chloride, trichlorethylene, hydrocarbons, e.g. benzene, toluene or cyclohexane, carboxylic acid esters, e.g. acetic acid ethyl ester and/or silicon tetraalkylates-or acetic acid anhydride.

When using mixtures 'with bicyelic acetals each with one acetal group per ring and/or with branched polyacetals, correspondingly branched ether group-containing c'opolycsters are formed. It was definitely not to be expected that the described acetals and acetal mixtures would react with ketcne in such a manner, because these, as is known, yield different products, dependingon the catalyst and the reaction conditions.

Moreover, it was surprising that each acetal group of a polymer molecule reacts with ketcne and that from an impure polymer starting substance it was possible to obtain an analysis-pure product.

The polyesters formed by our process are suitable, among other uses, for use as softeners for plastics and for the manufacture of polyester resins.

EXAMPLE 1 Fifty-one g. of l, 3-dioxepane were polymerized by adding 1.5 ml. boron trifluoride etherate at room temperature and dissolved in'l50 ml: ether. Forty-five g. ketcne were piped through this-solution at 2040 C. The solution took up 22 g. ketcne, and the reaction mixture turned red. After neutralizing with sodium acetate it was washed out with water and at l60-170 C. it wastreed of the low, boiling components. The remainder was the polyester that was formed with a percent yield: (a viscous yellow oil molecular weight 1,090) Hydroxyl number: 14.6 acid number: 18.5

Analysis: Actual Com uted 1%) C 57.81 58.33 H 8.80 K33 EXAMPLE 2 During the fracti'onating of 5, 5-dimethyl-l,3-di0xan, 40 percent of a no longer distillablc, polymerized, waxlike acetal remained in the still? Without further purification, 50 g. of this substance was dissolved in ISO'mL-dry methylene chloride. 20 g. ketcne was piped through this solution at 20 C. 0.5 ml. hexafluorophosphoric acid was used as a catalyst. The processing was done in the same manner as in example I. The yield (a viscous yellow oil, molecular weight about 1,350) 83 percent.

A nah-w. Actual ('71 Computed Analysis: Actual (36) Computed ('14 :056 60.76 c 60.09 59.69 H 06 8.86 H 3.05 8.06

. The invention claimed is: EXAMPLP 3 1. Process for making copolyesters containing ethcr groups,

The same as when making 5,5-dimcthyl-l,3-dioxan, a conand Ofthe general formula siderable quantity (about 30 percent) of a no longer distillable product likewise remained in the still during the processing of 10 r- 2-phenyl-5-5-dimethyl-13-dioxan. 50 g. of this residue was dis- T-(UW).. bT solved together with 4.5 ml. boron trifluoride dietherate as L catalyst, in 150 ml. dry benzene, and 12 g. ketene was piped through this solution at 5 C. The processing was done in the which Comprises reacting polyacctms having the structural same manner as in example I. The yield a yellowish resin, brit- 15 unit 110 at room temperature, molecular weight about 1,450 was 85 percent. AO-CHR'-O- alone or in admixture with cyclic acctals of the general formu- Analysis: Actual (91;) Computed (9%) Id c 71.55 71.79 H 8.00 7.69 H

EXAMPLE4 A solution of 970 g. of polymerized 1,3-dioxepane and 2 ml.

boron trifluoride etherate in 1460 ml. methylene chloride R R 2-1 were pumped into a reactor, into which molar quantities of ketene were piped at the same time, with an input speed of 150 t hour" This coniesponded to a Staying penod of with ketene in the presence of a catalyst selected from the about 80 i The reacuon temperature was kept at 27L group consisting of mineral acids and Friedel-Crafts catalysts by coolmg' The reaction Product was freed from the at temperatures between -80 and 160C. in which formulas catalyst by means of an ion exchanger and was obtained after withdrawal of the solvent and of the low molecular components at 120 C. in a vacuum in the form of a light, orange 35 VIZ-OH, *COOH, OCO CH2- C0O"COCH2 colored viscous oil. This copolyether ester (a viscous, orange- U O A O colored oil, molecular weight about 1,210) corresponded in V="OA 0-CH2 its physical properties to what is described in example 1. w COCHCHR'0'-A CHR" CH2 C0' 2 EXAMPLE 5 40 l 'l f Through a solution of 25 g. of 5,5-dimethyl-l,3-dioxan and l l1-2 M 25 g. of the polyacetals made from benzaldehyde and diethylene glycol in 150 ml. methylene chloride, 30 g. ketene a=0 25 was P p at C in the Presence of b =0-50 with the proviso that a and b cannot be zero at the afluorophosphoric acid over a period of 1 hour. The reaction Same time solution was neutralized with sodium acetate, washed with :140 water and freed of the low boiling components at 120 C. and R: lk l residues, H 11 mm. Hg. Yield: 90 percent of theory. Molecular weight: '=H h 620 2. Process according to claim 1, in which the catalyst is a fluorophosphoric acid.

3. Process according to claim 1, characterized by the fact Maw, pm Cnmpuwd We) that the catalyst is used in quantities of 0.05 percent to 7 per- (1 62.75 63.28 cent, referred to the starting substance. H 4. Process according to claim 1, characterized by the fact that the reaction is performed in a solvent selected from the EXAMPLE 6 group consisting of hydrocarbons chlorinated hydrocarbons,

carboxylic acid alkyl esters and silicon tetraalkylates.

Thirty g. ketene were piped at 0 C. over a period of 1 ho r 5. Process for making copolyestcrs containing ether groups into a solution of 10 g. of the polyacetal made from benzalwhich comprises reacting polyacetals, alone or in admixture dehyde and diethylene glycol, 40 g. 4-methyl-1,3-dioxane and with cyclic acetals, with ketene in the presence of an acid 0.5 g. hexafluorophosphoric acid in 150 ml. methylene catalyst selected from the group consisting of mineral acids chloride. The processing was done in the same manner as in and Friedel-Craft catalysts, at a temperature between 80and example 5. Yield: 95 percent of theory. 160 C. 

2. Process according to claim 1, in which the catalyst is a fluorophosphoric acid.
 3. Process according to claim 1, characterized by the fact that the catalyst is used in quantities of 0.05 percent to 7 percent, referred to the starting substance.
 4. Process according to claim 1, characterized by the fact that the reaction is performed in a solvent selected from the group consisting of hydrocarbons, chlorinated hydrocarbons, carboxylic acid alkyl esters and silicon tetraalkylates.
 5. Process for making copolyesters containing ether groups which comprises reacting polyacetals, alone or in admixture with cyclic acetals, with ketene in the presence of an acid catalyst selected from the group consisting of mineral acids and Friedel-Craft catalysts, at a temperature between -80*and 160* C. 